We study the anisotropic response of highly oriented pyrolytic graphite (HOPG) in mid-infrared range, utilizing the potential of spectroscopic ellipsometry. We aim at the parameters of the infrared-active vibrations of E(1u) and A(2u) symmetry, and examine the phenomena related to the strong uniaxial anisotropy of HOPG. We explain the appearance of the weakly polar out-of-plane vibration in the elipsometric spectra taken on cleaved planes. We find a detectable Fano-type behavior of the in-plane phonon. (C) 2011 Elsevier B.V. All rights reserved.